Photos To Reveal Effects Of Rat Eradication

gugh sandbarAround 20 volunteers have spent the last two weeks on St Agnes and Gugh monitoring the impact of the rat eradication work.

The RSPB-funded project, worth almost £1m, began last autumn and aims to rid those islands of brown rats. It is being done to protect the internationally significant breeding grounds of Manx shearwater and storm petrel.

Project Manager Jaclyn Pearson says the team has been taking photographs at fixed points, which will eventually reveal whether the removal of the rodents has alerted the landscape.

Jaclyn says people probably assume rats wouldn’t have a big impact on the appearance of an area. She says they eat flowering seed heads and wiping out over 3,500 rats is likely to have an impact on the vegetation growing there.

Most projects that have tried to eradicate rodents on whole islands have only monitored the seabird populations, but this project is taking a wider survey of the effects on all aspects of the ecology.

Jaclyn admits though that the recent storms make interpreting the fixed-point photographs difficult because so much changed last winter.

Seabird Ecologist Dr Vickie Heaney says they’ve also been recording the numbers of occupied Manx shearwater burrows

The volunteers do this by playing the bird’s call into the burrows. The majority of birds will respond to the signal.

Vickie has been monitoring Manx shearwaters on St Agnes and Gugh for 10 years and she’s pleased that two were heard calling back from burrows that haven’t been occupied in recent years.

They’ve previously been considered homes to rats but now it seems they have found new tenants.